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Occupational Asthma among Car Painters in Parakou city in Benin, West Africa
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Background. Automobile spray painters in Nigeria are exposed to organic solvents due to the hazardous nature of their work. Inadequate use of personal protective equipment (PPE) may intensify exposure to high levels of chemical hazards with resultant health problems.
Objectives. The present study assessed PPE use and work practices and compared work-related health problems of spray painters and controls in Ile-Ife, Nigeria.
Methods. A cross-sectional study was conducted among 120 spray painters and 120 controls (electronic technicians). Data on socio-demographics, work practices, knowledge about organic solvent-related hazards and self-reported health symptoms were obtained using a semi-structured questionnaire. Clinical examinations were performed for all respondents and the composition of organic solvents in paints and paint products were derived from material safety data sheets.
Results. All respondents were male, and the mean age was 32.7±13.8 years for painters and 33.9±15.5 years for controls. Few (7.5%) painters perceived their use of PPE to be adequate. All spray painters worked in enclosed workshops and N-butyl acetate was the most commonly used organic solvent. Spray painters reported excessive tear production, recurrent cough, and short-term memory loss more frequently than controls (P
Purpose of Review
Occupational rhinitis (OR), an inflammatory disease of the nose, refers to any nasal symptoms reported to be work-related. The purpose of this review is to provide a current overview of the classification, diagnosis, and treatment of OR.
Recent Findings
Occupational rhinitis (OR) can further be classified into allergic or non-allergic depending on the causative agent(s) and pathogenesis. Presenting symptoms are similar to non-OR including nasal congestion, anterior and posterior rhinorrhea, sneezing, and nasal itching. Despite its high prevalence in a spectrum of workplaces, OR is under reported as it is often considered a nuisance rather than a potential precursor to occupational asthma (OA). The diagnosis of OR is obfuscated as it is difficult to determine if this condition was caused by environmental determinants in or outside the workplace. Furthermore, workers may have a pre-existing history of allergic or non-allergic rhinitis leading the clinician and worker to overlook inciting agents in the workplace. In this case, a diagnosis of OR is still possible depending on the exposures but must be differentiated from work-exacerbated rhinitis. Further complicating the diagnosis of OR is the lack of evidence-based research focused on this condition as it is often trivialized due to the perception that it has an insignificant impact on the worker’s health. The reality is that OR can have a significant impact on the worker’s quality of life and is associated with a number of comorbidities including occupational asthma, recurrent sinusitis, headaches, eustachian tube dysfunction, and sleep disorders similar to non-occupational rhinitis. However, one significant difference between these disorders is that workers diagnosed with OR are eligible for worker’s compensation. Treatment of OR involves avoidance of the inciting agent(s) and medications similar to those used to treat non-OR conditions.
Summary
This review summarizes recent progresses on the etiology, risk factors, diagnosis, and therapy of OR. In addition, suggested areas of further research with potential targets for modifications in the workplace environment as well as therapeutic interventions will be discussed.
Background: Asthma affects millions of people worldwide, with many patients experiencing symptoms that affect their daily lives despite receiving long-term controller medication.
Purpose: Work is a large part of most people’s lives, hence this study investigated the impact of uncontrolled asthma on work productivity in adults receiving asthma maintenance therapy.
Patients and methods: An online survey was completed by employed adults in Brazil, Canada, Germany, Japan, Spain and the UK. Participants were confirmed as symptomatic using questions from the Royal College of Physicians’ 3 Questions for Asthma tool. The survey contained the Work Productivity and Activity Impairment – Specific Health Problem questionnaire and an open-ended question on the effect of asthma at work.
Results: Of the 2,055 patients on long-term maintenance therapy screened, 1,598 were symptomatic and completed the survey. The average percentage of work hours missed in a single week due to asthma symptoms was 9.3%, ranging from 3.5% (UK) to 17.4% (Brazil). Nearly three-quarters of patients reported an impact on their productivity at work caused by asthma. Overall work productivity loss (both time off and productivity whilst at work) due to asthma was 36%, ranging from 21% (UK) to 59% (Brazil). When asked how asthma made participants feel at work, many respondents highlighted how their respiratory symptoms affect them. Tiredness, weakness and mental strain were also identified as particular challenges, with respondents describing concerns about the perception of colleagues and feelings of inferiority.
Conclusions: This study emphasizes the extent to which work time is adversely affected by asthma in patients despite the use of long-term maintenance medication, and provides unique personal insights. Strategies to improve patients’ lives may include asthma education, optimizing asthma management plans and running workplace well-being programs. Clinicians, employers and occupational health teams should be more aware of the impact of asthma symptoms on employees, and work together to help overcome these challenges.
Objective
The objective is to provide an evidence-based compendium of allergenic and irritant agents that are known to cause occupational asthma in order to improve diagnostics and disease management.
Methods
Two previously published reviews from our group utilized database searches to identify studies which were then rated according to the Scottish Intercollegiate Guideline Network (SIGN) grading system. The evidence level for each causative agent or worksite was graded using the Royal College of General Practitioners (RCGP) three-star system.
Results
Approximately 3,000 relevant papers were identified, which covered 372 different causes of allergic and 184 different causes of irritant occupational asthma. The highest level achieved using the SIGN grading system was 2++, indicating a high quality study with a very low risk of confounding or bias and a high probability of a causal relationship. Using the modified RCGP three-star grading system, the strongest evidence of association with an individual agent or worksite ('***') was found for exposure to laboratory animals. Associations with moderate evidence level (‘**’) were obtained for a) the allergenic agents or worksites: alpha-amylase from Aspergillus oryzae, various enzymes from Bacillus subtilis, papain, bakeries, western red cedar, latex, psyllium, storage mites, rat, carmine, egg proteins, Atlantic salmon, fishmeal, Norway lobster, prawn, snow crab, seafood, trout and turbot, reactive dyes, b) the irritant agents or worksites: benzene-1,2,4-tricarboxylic acid, 1,2- anhydride [trimellitic anhydride], chlorine, cobalt, cement, environmental tobacco smoke, grain, welding fumes, construction work, swine confinement, World Trade Center disaster 2001, and c) agents or worksites causing allergic as well as irritant occupational asthma, included farming, poultry confinement, various isocyanates and platinum salts. A low evidence level (RCGP) was obtained for 84 agents or worksites (42 from each group), providing a total of 141 conditions with a low, moderate or strong evidence level.
Conclusion
This work comprises the largest compendium and evaluation of agents and worksites causing allergic or irritant occupational asthma from the literature assessed in an evidence-based manner.
The aim of the European Respiratory Society work-related asthma guidelines is to present the management and prevention options of work-related asthma and their effectiveness.
Work-related asthma accounts for 5–25% of all adult asthma cases and is responsible for a significant socioeconomic burden. Several hundred occupational agents, mainly allergens but also irritants and substances with unknown pathological mechanisms, have been identified as causing work-related asthma.
The essential message of these guidelines is that the management of work-related asthma can be considerably optimised based on the present knowledge of causes, risk factors, pathomechanisms, and realistic and effective interventions. To reach this goal we urgently require greatly intensified primary preventive measures and improved case management. There is now a substantial body of evidence supporting the implementation of comprehensive medical surveillance programmes for workers at risk. Those workers who fail surveillance programmes need to be referred to a clinician who can confirm or exclude an occupational cause. Once work-related asthma is confirmed, a revised risk assessment in the workplace is needed to prevent further cases. These new guidelines confirm and extend already existing statements and recommendations.
We hope that these guidelines will initiate the much-needed research that is required to fill the gaps in our knowledge and to initiate substantial improvements in preventative measures.
Work-related asthma, which includes occupational asthma and work-aggravated asthma, has become one of the most prevalent occupational lung diseases. These guidelines aim to upgrade occupational health standards, contribute importantly to transnational legal harmonisation and reduce the high socio-economic burden caused by this disorder.
A systematic literature search related to five key questions was performed: diagnostics; risk factors; outcome of management options; medical screening and surveillance; controlling exposure for primary prevention. Each of the 1,329 retrieved papers was reviewed by two experts, followed by Scottish Intercollegiate Guidelines Network grading, and formulation of statements graded according to the Royal College of General Practitioners’ three-star system.
Recommendations were made on the basis of the evidence-based statements, which comprise the following major evidence-based strategic points. 1) A comprehensive diagnostic approach considering the individual specific aspects is recommended. 2) Early recognition and diagnosis is necessary for timely and appropriate preventative measures. 3) A stratified medical screening strategy and surveillance programme should be applied to at-risk workers. 4) Whenever possible, removing exposure to the causative agent should be achieved, as it leads to the best health outcome. If this is not possible, reduction is the second best option, whereas respirators are of limited value. 5) Exposure elimination should be the preferred primary prevention approach.
Diisocyanates, highly reactive monomers which cross-link polyurethane, are the most widely recognized causes of occupational asthma. Many exposed workers are end-users, including autobody spray painters who form a large population at risk. Neither the factors which determine incidence rate nor strategies for control have been adequately studied in this setting. We have conducted a cross-sectional survey of 23 (about one in five) autobody shops in the New Haven area to determine the feasibility of clinical epidemiological studies in this population. Among 102 workers, there was a high rate of airway symptoms consistent with occupational asthma (19.6%). Symptoms were most prevalent among those with the greatest opportunity for exposure (dedicated spray painters) and least among office workers; part-time painters had intermediate rates. Atopy was not associated with risk while smoking seemed to correlate with symptoms. Regular use of air-supplied respirators appeared to be associated with lower risk among workers who painted part- or full-time. We were unable to validate the questionnaire responses with peak expiratory flow record data attempted on a 1/3 sample of the workers. Despite intensive training and effort, subject compliance was limited. Among those who provided adequate data (24 of 38), only two demonstrated unequivocal evidence of labile airways; two others demonstrated lesser changes consistent with an occupational effect on flow rates. There was no clear association between these findings and either questionnaire responses or exposure classification. Overall, the survey suggests that there is a high prevalence of airway symptoms among workers in autobody shops, at least in part due to work-related asthma. However, there is need for both methodological and substantive research in this setting to document rates of occupational asthma and to develop a scientific basis for its effective control.
Serial peak expiratory flow (PEF) measurement is usually the most appropriate first step in the confirmation of occupational asthma. Visual assessment of the plotted record is more sensitive and specific than statistical methods so far reported. The use of visual analysis is limited by lack of widespread expertise in the methods. A computer assisted diagnostic aid (OASYS-2) has been developed which is based on a scoring system developed from visual analysis. This removes the requirement for an experienced interpreter and should lead to the more widespread use of the technique.
PEF records were collected from workers attending an occupational lung disease clinic for investigation of suspected occupational asthma and from workers participating in a study of respiratory symptoms in a postal sorting office. PEF records were divided into two development sets and two gold standard sets. The latter consisted of records from workers in which a final diagnosis had been reached by a method other than PEF recording. An experienced observer scored individual work and rest periods for the two development set PEF records; linear discriminant analysis was used to compare measurements taken from development set 1 records with visual scores. Two equations were produced which allowed prediction of scores for individual work or rest periods. The development set 2 was used to determine how these scores should be used to produce a whole record score. The first gold standard set was used to determine the whole record score which best separated those with and without occupational asthma. The second set determined the sensitivity and specificity of the chosen score.
Two hundred and sixty eight PEF records were collected from 169 workers and divided into two development sets (81 and 60 records) and two gold standard sets (60 and 67 records). Linear discriminant analysis produced equations predicting the score for work periods incorporating five indices of PEF change and one for rest periods using seven indices. These equations correctly predicted the score for development set 1 work and rest periods on 61% of occasions (kappa = 0.47). The whole record score for development set 2 records, after weighting for definite or definitely no occupational effect, correlated with the visual score (correlation coefficient 0.86). Comparison with gold standard set 1 identified a cut off which proved to have a sensitivity of 75% and a specificity of 94% for an independent diagnosis of occupational asthma when applied to gold standard set 2.
These results suggest that the sensitivity and specificity of analysing PEF records for occupational asthma using OASYS-2 approaches that of visual analysis, but it should be absolutely reproducible. The performance of OASYS-2 is more specific and approaches the sensitivity of other statistical methods of analysis. The evaluation of a large number of PEF records from workers exposed to different sensitising agents suggests that these results should be robust and should be repeatable in clinical practice.
Occupational asthma is the most common form of occupational lung disease in the developed world at the present time. In this review, the epidemiology, pathogenesis/mechanisms, clinical presentations, management, and prevention of occupational asthma are discussed. The population attributable risk of asthma due to occupational exposures is considerable. Current understanding of the mechanisms by which many agents cause occupational asthma is limited, especially for low-molecular-weight sensitizers and irritants. The diagnosis of occupational asthma is generally established on the basis of a suggestive history of a temporal association between exposure and the onset of symptoms and objective evidence that these symptoms are related to airflow limitation. Early diagnosis, elimination of exposure to the responsible agent, and early use of inhaled steroids may play important roles in the prevention of long-term persistence of asthma. Persistent occupational asthma is often associated with substantial disability and consequent impacts on income and quality of life. Prevention of new cases is the best approach to reducing the burden of asthma attributable to occupational exposures. Future research needs are identified.
Oasys-2 is a validated diagnostic aid for occupational asthma that interprets peak expiratory flow (PEF) records as well as generating summary plots. The system removes inconsistency in interpretation, which is important if there is limited agreement between experts. A study was undertaken to assess the level of agreement between expert clinicians interpreting serial PEF measurements in relation to work exposure and to compare the responses given by Oasys-2.
35 PEF records from workers under investigation for suspected occupational asthma were available for review. Records included details of nature of work, intercurrent illness, drug therapy, predicted PEF, rest periods, and holidays. Simple plots of PEF and the Oasys-2 generated plots were available. Experts were advised that approximately 1 hour was available to review the records. They were asked to score each work-rest-work (WRW) period and each rest-work-rest (RWR) period for evidence of occupational effect. At the end of each record scores of 0-100% were given for evidence of "asthma" and "occupational effect" for the whole record. Kappa values were calculated for each scored period and for the opinions on the whole record. The scores were converted into four groups (0-25%, 26-50%, 51-75%, 76-100%) and two groups (0-50% and 51-100%) for analysis. This is relevant to scores produced by Oasys-2. Agreement between Oasys-2 scores and each expert was calculated.
24 of 35 records were analysed by seven experts in the allotted time. For whole record occupational effect, median kappa values were 0.83 (range 0.56-0.94) for two groups and 0.62 (0.11-0.83) for four groups. For asthma, median kappa values were 0.58 (0-0.67) and 0.42 (0.15-0.70) for two and four groups respectively. For all WRW and RWR periods kappa values were 0.84 (0.42-0.94) and 0.70 (0.46-0.87) respectively. Agreement between Oasys-2 and individual experts showed a median kappa value of 0.75 (0.50-0.92) for two groups and 0.50 (0.39-0.70) for four groups. Kappa values for the median expert score v Oasys-2 were 0.75 for two groups and 0.67 for four groups. Agreement was poor for records with intermediate probability, as defined by Oasys-2.
Considerable variation in agreement was seen in expert interpretation of occupational PEF records which may lead to inconsistencies in diagnosis of occupational asthma. There is a need for an objective scoring system which removes human variability, such as that provided by Oasys-2.
To estimate the general and specific incidence of occupational asthma in France in 1996-99; and to describe the distribution of cases by age, sex, suspected causal agents, and occupation.
New cases of occupational asthma were collected by a national surveillance programme, based on voluntary reporting, named Observatoire National des Asthmes Professionnels (ONAP), involving a network of occupational and chest physicians. For each case, the reporting form included information on age, sex, location of workplace, occupation, suspected causal agent, and methods of diagnosis. Estimates of the working population, used to calculate incidence rates by age, sex, region, and occupation, were obtained from the Institut National de la Statistique et des Etudes Economiques (INSEE) and from the French Securite Sociale statistics.
In 1996-99, 2178 cases of occupational asthma were reported to the ONAP, giving a mean annual rate of 24/million. Rates in men were higher than rates in women (27/million versus 19/million). The highest rate was observed in the 15-29 years age group (30/million). The most frequently incriminated agents were flour (20.3%), isocyanates (14.1%), latex (7.2%), aldehyde (5.9%), persulphate salts (5.8%), and wood dusts (3.7%). The highest risks of occupational asthma were found in bakers and pastry makers (683/million), car painters (326/million), hairdressers (308/million), and wood workers (218/million).
Despite likely underreporting, the number of cases of occupational asthma reported to the ONAP was approximately twice the number of compensated cases over the same period. The relevance of the programme is confirmed by the reproducibility of the results year after year, and its consistency with other surveillance programmes. The ONAP programme is useful for the identification of targets for primary prevention.
Occupational asthma is the most common occupational lung disease in industrialised countries, and the second most common occupational lung disease reported after pneumoconioses in developing countries. The median proportion of adult cases of asthma attributable to occupational exposure is between 10% and 15%. The population attributable fraction appears to be similar in industrialised and developing countries characterised by rapid industrialisation (13-15%), but lower in less industrialised developing countries (6%). The high-risk occupations and industries associated with the development of occupational asthma vary depending on the dominant industrial sectors in a particular country. High-risk exposure to cleaning agents and pesticide exposure in developing countries appear to be as important as exposure to isocyanates, cereal flour/grain dust, welding fumes, wood dust and, more recently, hairdressing chemicals, commonly reported in industrialised countries. The reported mean annual incidence of occupational asthma in developing countries is less than 2 per 100 000 population, compared to very high rates of up to 18/100 000 in Scandinavian countries. While occupational asthma remains under-recognised, especially in developing countries, it remains poorly diagnosed and managed and inadequately compensated worldwide. Primary and secondary preventive strategies should be directed at controlling workplace exposures, accompanied by intense educational and managerial improvements. Appropriate treatment remains early removal from exposure to ensure that the worker has no further exposure to the causal agent, with preservation of income. However, up to one third of workers with occupational asthma continue to remain exposed to the causative agent or suffer prolonged work disruption, discrimination and risk of unemployment.
Associations between oligomeric isocyanate exposure, sensitization, and respiratory disease have received little attention, despite the extensive use of isocyanate oligomers.
To investigate exposure-response relationships of respiratory symptoms and sensitization in a large population occupationally exposed to isocyanate oligomers during spray painting.
The prevalence of respiratory symptoms and sensitization was assessed in 581 workers in the spray-painting industry. Personal exposure was estimated by combining personal task-based inhalatory exposure measurements and time activity information. Specific IgE and IgG to hexamethylene diisocyanate (HDI) were assessed in serum by ImmunoCAP assay and enzyme immunoassays using vapor and liquid phase HDI-human serum albumin (HDI-HSA) and HSA conjugates prepared with oligomeric HDI.
Respiratory symptoms were more prevalent in exposed workers than among comparison office workers. Log-linear exposure-response associations were found for asthmalike symptoms, chronic obstructive pulmonary disease-like symptoms, and work-related chest tightness (prevalence ratios for an interquartile range increase in exposure of 1.2, 1.3 and 2.0, respectively; P </= 0.05). The prevalence of specific IgE sensitization was low (up to 4.2% in spray painters). Nevertheless, IgE to N100 (oligomeric HDI)-HSA was associated with exposure and work-related chest tightness. The prevalence of specific IgG was higher (2-50.4%) and strongly associated with exposure.
The results provide evidence of exposure-response relationships for both work-related and non-work-related respiratory symptoms and specific sensitization in a population exposed to oligomers of HDI. Specific IgE was found in only a minority of symptomatic individuals. Specific IgG seems to be merely an indicator of exposure.
Objectives
To identify all cases of occupational asthma in the literature and/or recognized as an occupational disease by the Social Security Fund of Senegal and analyze the various obstacles related to diagnosis and medicolegal aspects.Means and methodologyThe identification of cases of occupational asthma was based on the tables of occupational diseases, statistics available at the social security fund and publications available at the level of bibliographic databases Pubmed and Hinari WHO.ResultsThe inter-ministerial decree no. 6048 of 21 July 1991 tables of occupational diseases, comprises 67 panels of which 12 are devoted to occupational asthma. In terms of available statistics on occupational diseases, the social security fund has acknowledged 36 cases of occupational asthma on the basis of table no. 39 in 83.3% (n = 30), no. 38 in Table 8, 3% (n = 3) and tables 15, 35 and 57 with 2.8% (n = 1). The literature reports three publications on occupational asthma to knowing two cases due to latex among healthcare staff officiating in five hospitals in Dakar, a case of organic isocyanate in an automobile painter and one case resulting from exposure to sulfur dioxide. The etiologic agents responsible are by order of importance ammonia, occupational allergens, nickel, aromatic amines and organic isocyanates. At the clinical phenotype, an asthma induced by irritants is noted in 83.3% (n = 30) and occupational asthma-type immunologic in 16.7% (n = 6). On the medicolegal, 97.3% (n = 36), cases have been identified in a declaration and recognition in social security fund.Conclusion
Occupational asthma in Senegal is characterized by an under-diagnosis and under-reporting, consequences of violations from the state, health organizations and workplace safety, health professionals and social partners in the workplace. This situation shows the need for advocacy, awareness, education and communication on the various obstacles noted in the management of this disease.
Logistic regression is one of the most common multivariate analysis models utilized in epidemiology. It allows the measurement of the association between the occurrence of an event (qualitative dependent variable) and factors susceptible to influence it (explicative variables). The choice of explicative variables that should be included in the logistic regression model is based on prior knowledge of the disease physiopathology and the statistical association between the variable and the event, as measured by the odds ratio. The main steps for the procedure, the conditions of application, and the essential tools for its interpretation are discussed concisely. We also discuss the importance of the choice of variables that must be included and retained in the regression model in order to avoid the omission of important confounding factors. Finally, by way of illustration, we provide an example from the literature, which should help the reader test his or her knowledge.
Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Objective:
Because of its high prevalence, early screening for occupational asthma (OA) is crucial. We aimed to evaluate the screening performance of the Occupational Asthma Screening Questionnaire-11 items (OASQ-11) in a clinical setting.
Methods:
Between January 2009 and December 2011, 169 workers referred for potential OA to our hospital completed the OASQ-11 and underwent workups to determine the final diagnosis. The discriminative abilities of the OASQ-11 as a whole and in relation to demographic and exposure parameters were determined by the area under the receiving operator characteristic curve (AUC).
Results:
Model 1, consisting of the OASQ's items, showed fair discrimination (AUC, 0.69; 95% confidence interval, 0.58 to 0.80). Addition of age and exposure duration to model 1 improved discrimination (AUC, 0.80; confidence interval, 0.72 to 0.88).
Conclusion:
A simple model consisting of the OASQ-11's items, age, and exposure duration could well discriminate subjects with OA in a clinical setting.
Occupational asthma (OA) is a respiratory disorder characterized by airway hyperreactivity caused by agents present in the workplace. For determination of the prevalence of OA among car and furniture painters exposed to isocyanate in the center of Eskisehir, Turkey, a clinical and epidemiologic prospective study in three phases was done, incorporating 312 (89.4%) of the painters.
Of these subjects, 190 (61%) were furniture painters and 122 (39%) automobile painters. In the first phase of the study, a modified questionnaire and pulmonary function test (PFT) were done. During the second phase, peak expiratory flow rate (PEFR) was monitored in 52 subjects whose complaints were confirmed and who agreed to a month of such monitoring. In the third phase, nonspecific bronchial provocation tests (NSBPT) with histamine were done on 23 of the PEFR-monitored workers.
Finally, through questionnaire, typical history, PFT, PEFR monitoring, and NSBPT, 30 workers (9.6%) were diagnosed as having OA. Smoking habits and atopy in the OA-diagnosed workers were found to be statistically significantly high in comparison to the other workers.
It was concluded that OA is a common disorder among automobile and furniture painters, and smoking habits and atopy were seen to have a significant effect on OA occurrence.
The nationwide Surveillance of Work-related and Occupational Respiratory Diseases in South Africa, SORDSA, was established in 1996 to provide systematic information on occupational respiratory diseases.
SORDSA's objectives are to monitor the nature, extent and distribution of occupational respiratory diseases, and to increase awareness of their diagnosis and prevention. This paper describes the programme and results obtained for occupational asthma in the first 2 years, ending in October 1998.
SORDSA identifies newly diagnosed cases of occupational respiratory disease through voluntary reporting by pulmonologists, occupational medicine doctors and occupational health nurses. Initially, recruitment of the above health care providers was done through the membership infrastructure of their respective professional societies. Booklets with prescribed monthly reporting forms were distributed annually to all reporting members and a core of reporting providers was established through a proactive method of data collection. Information dissemination and reporting feedback takes place through quarterly newsletters and issue-specific brochures on certain hazardous agents.
Over the initial 2-year period, 3285 cases of occupational respiratory disease were reported to SORDSA by 203 doctors and 97 occupational health nurses. After pneumoconiosis and associated respiratory conditions, occupational asthma was the second most commonly reported disease with 225 cases (6.9%). The average annual incidence for occupational asthma in South Africa was 13.1 per million employed people, with the highest incidence reported from the Western Cape province (37.6 per million). Latex was the most frequently reported agent for occupational asthma, followed by isocyanates and platinum salts. Low molecular weight agents accounted for 59.6% of the cases of occupational asthma.
The results from this initial phase show that despite some limitations, SORDSA has the potential to obtain useful data on the industries, agents and occupations causing occupational asthma in South Africa.
Occupational asthma (OA) is one of the leading causes of pulmonary diseases and has been extensively studied in adults. Childhood employment, a significant problem in many developing countries, should be studied to determine and evaluate its effects on psychosocial and lung health. In order to investigate the presence of work-related asthma-like symptoms and OA in apprentice adolescent car painters, 72 adolescents between the ages of 15-20 yr studying in Vocational Training Centres of Ankara were investigated using questionnaire, pulmonary function test (PFT), serial peak expiratory flow (PEF) measurements and methacholine inhalation tests. As a control group, 72 adolescents studying in Industrial and Commercial Training Centres located in the same environment were investigated with questionnaire and PFT. Almost 50% of the study group had work-related asthma-like symptoms for which occupational dermatitis history was predictive [odds ratio: 2.9 (1.026-8.13) (95% confidence interval)]. Seventeen of 22 with serial PEF measurements showed a variability of > or =20% and three (4.2%) of 12 tested with methacholine inhalation test had a PC20 < or = 8 mg/ml, which led to the diagnosis of OA. There was no statistically significant difference between study and control groups in terms of PFT. In conclusion, the high prevalence of work-related asthma-like symptoms among adolescent car painters clearly indicates the need for routine follow-up of adolescent workers for lung health.
Isocyanates, reactive chemicals used to generate polyurethane, are a leading cause of occupational asthma worldwide. Workplace exposure is the best-recognized risk factor for disease development, but is challenging to monitor. Clinical diagnosis and differentiation of isocyanates as the cause of asthma can be difficult. The gold-standard test, specific inhalation challenge, is technically and economically demanding, and is thus only available in a few specialized centers in the world. With the increasing use of isocyanates, efficient laboratory tests for isocyanate asthma and exposure are urgently needed.
The review focuses on literature published in 2005 and 2006. Over 150 articles, identified by searching PubMed using keywords 'diphenylmethane', 'toluene' or 'hexamethylene diisocyanate', were screened for relevance to isocyanate asthma diagnostics. New advances in understanding isocyanate asthma pathogenesis are described, which help improve conventional radioallergosorbent and enzyme-linked immunosorbent assay approaches for measuring isocyanate-specific IgE and IgG. Newer immunoassays, based on cellular responses and discovery science readouts are also in development.
Contemporary laboratory tests that measure isocyanate-specific human IgE and IgG are of utility in diagnosing a subset of workers with isocyanate asthma, and may serve as a biomarker of exposure in a larger proportion of occupationally exposed workers.
Les principaux métiers en cause
- J Ameille
The Prevalence of Occupational Asthma in Car Painters
- S Özkurt
- M Zencir
- M Hacioglu
- R Altin
- F Fisekci